Protocadherin 11 Y-linked (PCDH11Y), a member of the cadherin superfamily, is predominantly expressed in the central nervous system, is encoded by the Yp11.2 locus and exists in three isoforms: 11Ya, 11Yb and 11Yc. PCDH11Y is upregulated by retinoic acid signalling and is essential for spermatogonial differentiation and initiation of meiosis. PCDH11Y mediates Wnt signalling, which plays a crucial role in the differentiation of various cell types. PCDH11Y has been implicated in neuronal cell differentiation and proliferation, but its association with spermatogenesis has not yet been addressed. Hence, in order to address the possible role of PCDH11Y in relation to spermatogenesis, the expression analysis of PCDH11Y in the seminal germ cells of fertile and infertile males were carried out employing RT-PCR, western blotting and immunofluorescence analysis. In the present study, PCDH11Yb, but not PCDH11Ya or PCDH11Yc, was expressed in germ cells isolated from the semen of all 13 men with proven fertility. However, in several subjects from various infertility classes, there was complete absence or a significant reduction in the expression of PCDH11Yb. PCDH11Y exhibited prominent localisation on the head and midpiece region of spermatozoa from fertile men, whereas spermatozoa from infertile subjects had either weak or abnormal localisation patterns for PCDH11Y. In addition, downregulation of canonical Wnt signalling was correlated with defective expression of PCDH11Y in spermatozoa of infertile men, as evidenced by downregulation of the Wnt targets C-Myc and C-Jun. In conclusion, expression levels of PCDH11Yb in germ cells in the semen were correlated with the fertility status of men.

Background. Over the last few years, the importance of leptin in energy metabolism has been extensively studied in both animal models and in humans. Very few results are available on the association between human leptin gene (LEP) variants and obesity traits in India. We designed this study to analyse the polymorphisms in human leptin gene and the association of sequence variants with obesity among the population in Kerala, South India. Methods. In this case-control design of 148 study participants, data were collected on socioeconomic aspects and anthropometric measurements. Plasma glucose, insulin, leptin, and lipid profile were measured. Genotyping was done by automated DNA sequencing. Results. The common Single Nucleotide Polymorphism (SNP) of 5′-UTR of LEP − 2548G/A was found to be present in the study population with “A” variant as dominant allele. A novel synonymous mutation Thr5Thr of exon 2 of LEP was identified in heterozygous form in one subject with morbid obesity with hyperleptinemia. A novel missense mutation Phe17Leu was observed in two subjects with obesity in heterozygous condition. A novel missense mutation Lys36Arg in exon 2 of LEP was observed in one subject with abdominal obesity and decreased serum leptin level. Conclusion. LEP − 2548G/A at 5′-untranslated region was found to be common with the mutant “A” variant in the study population. SNPs of exons in LEP were found to be rare but associated with morbid obesity and altered levels of serum leptin in the study population in Kerala, India.